ELFN1 and attention deficit-hyperactivity disorder: Of note, ELFN1 mutations clustered in the region required for mGlu7 recruitment have been found in patients with epilepsy and ADHD (Dolan and Mitchell, 2013; Tomioka et al., 2014), and ELFN1 knockout (Elfn1-/-) animals exhibit a similar seizure phenotype to Grm7-/- animals (Tomioka et al., 2014).